Beersmith 3 Mash Efficiency Issues

[Ylbc]

Hey guys,

Hope someone can help, I'm pulling my hair out trying to make sense of Beersmith. I brew with the Unibrau, and I can NEVER get my mash efficiencies and gravities right. I have spent a couple of hours figuring out the volumes and losses for my setup, they are here:

With no diptube, i leave behind about 1.5 gallons of wort. Which isnt awesome, but I have it accounted for. My concern comes with a recent recipe I brewed. I purposely set my Brewhouse efficiency low to try and account for mash efficiency, and here is what I dont understand.

It estimated my mash efficiency at around 75%, but my measured came in at 46%. This isnt the big deal, but what is, was my brewhouse efficiency was almost right in line:

So then lets say my mash efficiency just sucks, but how would I account for that here?

Here is the grain bill as well:

Any help here on what I am doing wrong would help.

 

[McKnuckle]

Mash efficiency is the multiplication of two percentages, conversion and lauter:

Actual pre-boil gravity points / Potential gravity points @ 100% conversion
multiplied by
Wort collected volume / total starting water volume

Since you are mashing and boiling in a single vessel, you do not lose any volume except to grain absorption. What value are you using for grain absorption? On average, it's about 0.12 gal/lb.​

Assuming you are in that range, the only factor affecting mash efficiency is your pre-boil gravity compared to the theoretical potential of your wort. How is that? I can't tell from the 1.030 value in your screenshot. Would need to know the potential at 100%. However, it looks like if you expected 1.048 and that was already a 75% mash efficiency estimation, then you really undershot that.

Brewhouse efficiency from that point can only go down. The remaining factor is your volume losses on the post-boil side (evaporation does NOT count). Divide the amount of wort you put into the fermenter by what was in the kettle post-boil, and then multiply that percentage times your mash efficiency. You gave up a ton of wort in relation to the batch size. So it is not surprising to see very low BH efficiency.

 

[Oginme]

Looking at your screen captures, you are entering the gravity data, but without the volume data this is meaningless with regard to efficiency calculations. You may be low because you are not drawing enough sugars from the grains, or because you have more volume coming from the mash than you anticipated in your equipment profile. Before you can make any meaningful adjustment to your efficiency numbers, you need to make sure you volumes are close to target.

 

[Ylbc]

Mash efficiency is the multiplication of two percentages, conversion and lauter:

Actual pre-boil gravity points / Potential gravity points @ 100% conversion
multiplied by
Wort collected volume / total starting water volume

Since you are mashing and boiling in a single vessel, you do not lose any volume except to grain absorption. What value are you using for grain absorption? On average, it's about 0.12 gal/lb.​

Assuming you are in that range, the only factor affecting mash efficiency is your pre-boil gravity compared to the theoretical potential of your wort. How is that? I can't tell from the 1.030 value in your screenshot. Would need to know the potential at 100%. However, it looks like if you expected 1.048 and that was already a 75% mash efficiency estimation, then you really undershot that.

Brewhouse efficiency from that point can only go down. The remaining factor is your volume losses on the post-boil side (evaporation does NOT count). Divide the amount of wort you put into the fermenter by what was in the kettle post-boil, and then multiply that percentage times your mash efficiency. You gave up a ton of wort in relation to the batch size. So it is not surprising to see very low BH efficiency.

Thats what my question is around. If my brewhouse effiency is close, but my mash efficiency is way off, how would i account for that moving forward? Meaning if I made a second batch, and wanted to account for the poor efficiency, how would i do that? According to Beersmith my brewhouse is within 1%, but my gravities are way off.

And for the volumes, this was a 2.5 Gallon batch, and the pre-boil volumes were spot on (and in the screenshot)

 

[Ylbc]

And here are my grain absorption rates

 

[TheMadKing]

Looking at your screen captures, you are entering the gravity data, but without the volume data this is meaningless with regard to efficiency calculations. You may be low because you are not drawing enough sugars from the grains, or because you have more volume coming from the mash than you anticipated in your equipment profile. Before you can make any meaningful adjustment to your efficiency numbers, you need to make sure you volumes are close to target.

this

Either you have a mash process issue where you are not extracting enough sugar from your grain, or you are ending up with far more water volume after your mash (preboil volume) than you are expecting.

I suspect that it's a mash process issue based on the numbers I'm seeing, and efficiency that low is probably mostly related to either your grain crush or channeling during a recirculating mash.

 

[McKnuckle]

I don't mean to overlook your follow up post, but I'm a little confused, so maybe this will help you troubleshoot it yourself. There are 3 measurable fractions involved in the brewhouse efficiency equation:

A) Actual gravity points / Potential gravity points
B) Wort volume into kettle / Starting water volume
C) Wort volume into fermenter / Wort volume post-boil after chilling

Multiplication gives you the two efficiencies that we commonly reference:

AB = mash efficiency
ABC = brewhouse efficiency

Plug some actual values into these to understand what's going on with your experiences.

 

[Ylbc]

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Either you have a mash process issue where you are not extracting enough sugar from your grain, or you are ending up with far more water volume after your mash (preboil volume) than you are expecting.

I suspect that it's a mash process issue based on the numbers I'm seeing, and efficiency that low is probably mostly related to either your grain crush or channeling during a recirculating mash.

I do get the grain crushed at a local store. [EDIT] Looked up channeling, thanks for the suggestions.

 

[kevin58]

Are those actual volumes or did you simply accept the equipment profile you found in Beersmith? You really need to take actual measurements from your system and customize that profile. Until you do, you will be chasing your tail every brew day.

All of your volume losses is what you want to measure... every where that you lose wort... grain absorption, mash tun dead space, boil off, loss to trub and chiller, fermenter loss... and probably a few I have forgotten.

Is the Unibrau a BIAB system? Then you may need to use a BIAB mash profile too.

 

[Ylbc]

Are those actual volumes or did you simply accept the equipment profile you found in Beersmith? You really need to take actual measurements from your system and customize that profile. Until you do, you will be chasing your tail every brew day.

All of your volume losses is what you want to measure... every where that you lose wort... grain absorption, mash tun dead space, boil off, loss to trub and chiller, fermenter loss... and probably a few I have forgotten.

Is the Unibrau a BIAB system? Then you may need to use a BIAB mash profile too.

Yes its BIAB, and i have a BIAB mash selected. I did do all the measurements myself, there was far less trub and volume loss space before i measured it.

 

[Oginme]

When I look at your screen shot of the sessions tab, your volumes for 'meas pre-boil vol' and 'meas batch size' are yellowed out, indicating that these are the default values and not actual measured values. These volume measurements are critical to getting the calculation for your efficiency in BeerSmith correct.

 

[Ylbc]

When I look at your screen shot of the sessions tab, your volumes for 'meas pre-boil vol' and 'meas batch size' are yellowed out, indicating that these are the default values and not actual measured values. These volume measurements are critical to getting the calculation for your efficiency in BeerSmith correct.

Sorry, realized i didnt update them, but the volume was spot on so i just left it. Adjusted it so its not the default:

 

[Oginme]

OK, I can accept that which then means that your post mash gravity reading is most likely a bad data point. There is no way you can start your boil with 4.8 gal of wort at 1.030 and end up at the end of the boil with 2.5 gal + 1.5 gal of 1.060 gravity wort. You are starting with 4.8 x 30 gravity points = 144 sugar points and ending with 4.0 x 60 = 240 sugar points. These number should be the same or very close. Part of this is from the addition of the dextrose which is at most 2 points in your recipe. That would account for 9.6 sugar points out of the 96 you are missing.

The only way this could happen is if your volume measurements are drastically off, which would be pretty evident to you or that you had a bad reading, which happens from time to time.

Are you using a hydrometer or refractometer to take your gravity readings?

 

[Ylbc]

OK, I can accept that which then means that your post mash gravity reading is most likely a bad data point. There is no way you can start your boil with 4.8 gal of wort at 1.030 and end up at the end of the boil with 2.5 gal + 1.5 gal of 1.060 gravity wort. You are starting with 4.8 x 30 gravity points = 144 sugar points and ending with 4.0 x 60 = 240 sugar points. These number should be the same or very close. Part of this is from the addition of the dextrose which is at most 2 points in your recipe. That would account for 9.6 sugar points out of the 96 you are missing.

The only way this could happen is if your volume measurements are drastically off, which would be pretty evident to you or that you had a bad reading, which happens from time to time.

Are you using a hydrometer or refractometer to take your gravity readings?

So I'm using a refractometer to take gravity measurements. It came in at 9.6 right after mashing but realized I didn't stir it and just took from the top of the kettle. They came in at 7.7 brix after stirring. I had calibrated at the beginning of the day. It's also one of those table top ones, not eye sight refractometer.

Also I made up the gravity difference with I think it was 1.9 lb of DME (sorry on mobile) to bring the gravity back up to 1.060 (after the brix to gravity conversion).

 

[Oginme]

That makes up the difference then.

Places I would look at next are: crush and mixing when doughing in.

For the crush, take out a small handful of grains on your next brew and inspect the intact grain kernels. Are they fractured inside or hard and whole? Are there a fair amount or are they hard to find in your sample? Crush is the single most influential factor in your mash efficiency.

For stirring: I stir in my grains for at least 5 to 10 minutes when doughing in. I create a turbulent surface when adding the grains to quickly wet out the particles as they hit the water. Following the addition, I mix with a bottom to top motion to bring up any dough balls which may have formed as the grain hit the water. These dough balls will not wet through easily and often remain dry inside after the mash is finished.

I also take at least three measurements when using my refractometer. A couple of drops from a large kettle of wort is a pretty small sample size and may not represent the full kettle of wort.

 

[Ylbc]

That makes up the difference then.

Places I would look at next are: crush and mixing when doughing in.

For the crush, take out a small handful of grains on your next brew and inspect the intact grain kernels. Are they fractured inside or hard and whole? Are there a fair amount or are they hard to find in your sample? Crush is the single most influential factor in your mash efficiency.

For stirring: I stir in my grains for at least 5 to 10 minutes when doughing in. I create a turbulent surface when adding the grains to quickly wet out the particles as they hit the water. Following the addition, I mix with a bottom to top motion to bring up any dough balls which may have formed as the grain hit the water. These dough balls will not wet through easily and often remain dry inside after the mash is finished.

I also take at least three measurements when using my refractometer. A couple of drops from a large kettle of wort is a pretty small sample size and may not represent the full kettle of wort.

Thanks for the hints on stirring, I don't stir for that long, and multiple samples. And I'll check the crush. Does this start to indicate too that I should look at my own crusher as well to gain consistency?

 

[Oginme]

I made a huge leap in consistency when I bought my corona type mill. The LHBS I was using is pretty good, but the owner admitted that they set the gap for around 75% efficiency on their recipes when brewed on most systems. Which was pretty much what I got. That means that other systems may get a little better or little worse. I found that double crushing at the LHBS gave me a minimal increase in efficiency as the grains that slid through the first time are just as likely to slip through again.

 

[Mayzer]

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Thats what my question is around. If my brewhouse effiency is close, but my mash efficiency is way off, how would i account for that moving forward? Meaning if I made a second batch, and wanted to account for the poor efficiency, how would i do that? According to Beersmith my brewhouse is within 1%, but my gravities are way off.

Mash performance issues aside. To answer your question on how to model your current system, your BH efficiency is actually around 25%. When you added the DME after the post mash reading you skewed the numbers with an adjusted Measured OG. This artificially boosted your BH efficiency. Set your BH efficiency around 25% and your Mash efficiency will be around 40% for the grain bill. Your numbers should be very close for the next batch without adding DME.

BTW Your Loss to Trub and Chiller (1.5gal) is the significant contributor to the difference between BH and Mash efficiencies. You're losing 38% of your batch to the dead space. If you could improve that with a dip tube, your BH efficiency would go up (no affect on Mash efficiency though).

 

[Ylbc]

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Mash performance issues aside. To answer your question on how to model your current system, your BH efficiency is actually around 25%. When you added the DME after the post mash reading you skewed the numbers with an adjusted Measured OG. This artificially boosted your BH efficiency. Set your BH efficiency around 25% and your Mash efficiency will be around 40% for the grain bill. Your numbers should be very close for the next batch without adding DME.

BTW Your Loss to Trub and Chiller (1.5gal) is the significant contributor to the difference between BH and Mash efficiencies. You're losing 38% of your batch to the dead space. If you could improve that with a dip tube, your BH efficiency would go up (no affect on Mash efficiency though).

My god thank you!! That makes so much more sense.

Yea trying to work through the massive losses. Tried a diptube, but accidentally burned out my heating elements because i moved too much liquid out from underneath the grain bed.